SysV Init
This process is responsible for launching all the other services running on a Linux (or any SysV Unix) system. This is the "mother of all processes".
/etc/inittab - the initialization file for the 'init' process. defines the default run-level, the program to run on system startup, etc. This file describes both actions to take when specific events occur (ctrl+alt+del was hit, UPS notified of power failure, system switched to a new run level), as well as processes to launch (and look after) in specific run-levels (e.g. xdm, getty).